Staple fiber has long been used as filling material, for support and/or insulating purposes. Polyester fiberfill has been a particularly desirable fiber for such purposes, because of its bulk, resilience, resistance to attack by mildew and other desirable features. Conventionally, fiberfill used to be processed in the form of batts, after the fibers were parallelized on a card (or garnett), because this was an economically attractive and useful way of handling fiberfill.
Recently, however, Marcus has disclosed in U.S. Pat. Nos. 4,618,531 and 4,783,364 how spirally crimped fiberfill can be formed into fiberballs that make a particularly desirable filling material, being lofty, soft and refluffable in a way that is similar to down filling. Marcus has also disclosed in U.S. Pat. No. 4,794,038 how fiberballs can be made similarly from blends of fiberfill with binder fiber, which can then be activated to make useful bonded support structures, e.g. for cushioning and mattresses. Marcus has disclosed a useful batch process and apparatus that takes advantage of the spirally crimped nature of his feed material for making such fiberballs, which are being produced commercially and have proved useful and interesting ball like fiber structures, because of their lofty nature, because they are easily transported by air conveying during processing, and because of the interesting and advantageous properties of the products, which may be processed into several interesting variants. We generally refer to these structures herein as fiber clusters.
An object of the present invention is to provide a process and apparatus that can be operated to provide such ball like clusters of fibers continuously at high throughputs. Another object is to provide a process and apparatus that does not necessarily require a special feed fiber, but can be operated satisfactorily also with regular polyester staple fiber, or indeed other fibrous materials, to form fiber clusters of such densities and uniformity as may be required. A further object is to provide a process and apparatus that may be used to form clusters from fibers of coarser denier, even above 10.
As will be noted hereinafter, we have made several modifications to a type of carding machine in order to achieve our results.